High Contrast, Wide Viewing Angles

07/06/2017 Rutronik

You can find passive displays everywhere: in cars, kitchen and household appliances, telephones, as well as gas, water, and electric meters. This is thanks to their long service lives, energy-saving properties, and the fact that custom modules can be designed simply and quickly. The higher the value the application is intended to convey, the more that the attention has to be placed on the contrast.

A display with a jet black background and a very high contrast ratio lends the application a higher aesthetic value; therefore, this is sought-after primarily in medicine, the automotive market, and for industrial applications. Specific high contrast displays, such as those offered by Yeebo, URT, DLC, Tianma, or Displaytech, fulfill this desire - frequently further combined with wide viewing angles.

Vertical Alignment (EBN = Enhanced Black Neumatic)

A display with a particularly jet back background, very high contrast ratio and pronounced viewing angle enables Vertical Alignment Technology to be used, e.g. by Tianma, Yeebo, or URT. In so doing, the backlighting does not necessarily have to be white; applications can be underscored by a different color that can be selected freely.

When it comes to this technology, the liquid crystals between the LCD panels are vertical to one another in the 'Off' mode. As soon as voltage is applied to the display, they turn to a vertical position - hence the description 'Vertical Alignment'. In this way, very low light transmission arises and thus creates an extremely black background.

Vertical Alignment Technology requires a limited number of segments and ideally static activation or MUX 1:4, however up to a maximum of MUX 1:8. It additionally requires sufficient power supply as permanent LED backlighting is mandatory due to the negative mode in display operation.

Whether it is Vertical Alignment or other monochrome technologies: passive LCDs fulfill practically any project requirement. A whole raft of aspects - ranging from the definition of the displayed segments or pixel assignment, through to external dimensions, active areas, temperature ranges, connection methods, backlighting types, and colors, right through to the addition of various add-ons such as frames, locking hooks, or in-prints - can be implemented quickly, simply, and effectively on a custom basis.

OLED modules

OLED modules do not require a backlight, as they are self-illuminating. In the process, they consume scarcely any power and are ideally suited to battery-powered applications or hand-held devices. With a high contrast of 2000:1, OLEDs provide a phenomenal contrast between the black background and colored display dots. The viewing angles are also unbeatable when compared to other display technologies: Thanks to an angle of up to 270°, they offer an 'around the clock' view with continuously strong contrast values. A further benefit is that the organic layer of an OLED is thinner, lighter, and more flexible than the crystalline layer of an LED or LCD, thus enabling slimmer and lighter designs to be created. Visionox/Yeebo, DLC, and Raystar stock a very extensive range of Passive Matrix OLEDs with sizes of 0.66" to 5.5" in various resolutions and colors.

A well-rounded product

The Active Matrix OLED Module from DLC exhibits a particularly modern look with a round shape, high resolution of 400 x 400 pixels, and a full color spectrum. The product is thus pre-destined for use in consumer goods, such as fitness gadgets, remote controls, or bicycle accessories. However, this module's benefits come to the fore in industrial settings too: Thanks to an improved image, compatibility with touch panels, and temperature stability of -20°C to 60°C during operation as well as -30°C to 70°C during storage, these modules are suitable also for machine operating areas in energy and medicine technology, not to mention similar applications.